References:
Install LEMP Server (Linux, Nginx, MySQL & PHP) in Linux Mint 17 / Ubuntu 14.04 / Debian 7.6
Setting up PHP-FastCGI and nginx? Don’t trust the tutorials: check your configuration! … I use “try_files $uri =404;“
The /bin/bash Theory -- Using Overlayfs With LXC

• The Ubuntu 14.04 LTS Container that I started from was created using the following command:

  $ sudo su
  # lxc-create -n 14lts64-nginx -t ubuntu-cloud -- -a amd64 -r trusty

  This produced the following output:

  ubuntu-cloudimg-query is /usr/bin/ubuntu-cloudimg-query
  wget is /usr/bin/wget
  --2015-05-20 13:20:58--  https://cloud-images.ubuntu.com/server/releases/trusty/release-20150506/ubuntu-14.04-server-cloudimg-amd64-root.tar.gz
  Resolving cloud-images.ubuntu.com (cloud-images.ubuntu.com)... 91.189.88.141, 2001:67c:1360:8001:ffff:ffff:ffff:fffe
  Connecting to cloud-images.ubuntu.com (cloud-images.ubuntu.com)|91.189.88.141|:443... connected.
  HTTP request sent, awaiting response... 302 Found
  Location: https://cloud-images.ubuntu.com/releases/trusty/release-20150506/ubuntu-14.04-server-cloudimg-amd64-root.tar.gz [following]
  --2015-05-20 13:20:59--  https://cloud-images.ubuntu.com/releases/trusty/release-20150506/ubuntu-14.04-server-cloudimg-amd64-root.tar.gz
  Reusing existing connection to cloud-images.ubuntu.com:443.
  HTTP request sent, awaiting response... 200 OK
  Length: 186816043 (178M) [application/x-gzip]
  Saving to: ‘ubuntu-14.04-server-cloudimg-amd64-root.tar.gz’
  
  100%[==========================================================>] 186,816,043 1.02MB/s   in 2m 18s 
  
  2015-05-20 13:23:17 (1.29 MB/s) - ‘ubuntu-14.04-server-cloudimg-amd64-root.tar.gz’ saved [186816043/186816043]
  
  Extracting container rootfs
  perl: warning: Setting locale failed.
  perl: warning: Please check that your locale settings:
  	LANGUAGE = "en_CA:en",
  	LC_ALL = (unset),
  	LANG = "en_CA.UTF-8"
      are supported and installed on your system.
  perl: warning: Falling back to the standard locale ("C").
  locale: Cannot set LC_CTYPE to default locale: No such file or directory
  locale: Cannot set LC_MESSAGES to default locale: No such file or directory
  locale: Cannot set LC_ALL to default locale: No such file or directory
  
  Current default time zone: 'America/Toronto'
  Local time is now:      Wed May 20 13:23:25 EDT 2015.
  Universal Time is now:  Wed May 20 17:23:25 UTC 2015.
  
  Container 14lts64-nginx created.

  # exit

• The default user & password for this just created container will be ubuntu & ubuntu

• Start this just created container & Log-in to it:

  $ sudo lxc-start -n 14lts64-nginx -d
  $ sudo lxc-console -n 14lts64-nginx

• Change the default password for the ubuntu user:

  $ passwd

  • set the password to something else (and remember it).
  • logout & log back in to ensure the password was set correctly.

• Install squid-deb-proxy & update the packages:

  $ sudo apt-get update
  $ sudo apt-get install squid-deb-proxy-client
  $ sudo apt-get upgrade

• install a current known working version of Nginx via a ppa:

  $ sudo add-apt-repository ppa:teward/nginx-1.6.3
  $ sudo apt-get update
  $ sudo apt-get install nginx

  which provided the following install information:

  The following NEW packages will be installed:
    fontconfig-config fonts-dejavu-core libfontconfig1 libgd3 libjbig0
    libjpeg-turbo8 libjpeg8 libtiff5 libvpx1 libxpm4 libxslt1.1 nginx
    nginx-common nginx-full
  0 upgraded, 14 newly installed, 0 to remove and 0 not upgraded.
  Need to get 2,784 kB of archives.
  After this operation, 9,037 kB of additional disk space will be used.
  Do you want to continue? [Y/n] 

• Check the version is the current version from the PPA:

  $ nginx -v

  which produces the following output

  nginx version: nginx/1.6.3

• In Chrome, entering the url http://14lts64-nginx.lxc/ produces a webpage like this:

• Change the Nginx configuration file to more reasonable values for a Workstation Container:

  $ sudo nano /etc/nginx/nginx.conf

  Edit the following lines

  user www-data;
  worker_processes 4;
  pid /run/nginx.pid;

  to contain this:

  user www-data www-data;
  worker_processes 1;
  pid /run/nginx.pid;

• Now restart the nginx service:

  $ sudo service nginx restart

• Finally, create a “not the default” test file – to ensure Nginx is really working as expected:

  $ sudo nano /var/www/html/test.html     # copy the below into this empty file

  <html>
  <head>
  
  </head>
  <body>
  <h1>Test File</h1>
  <p>If this is on the screen, then test.html is working.</p>
  </body>
  </html>

• In Chrome, entering the url http://14lts64-nginx.lxc/test.html produces a webpage like this:

• install php5-fpm:

  $ sudo apt-get install php5-fpm php5-cli php5-gd php5-mcrypt php5-sqlite

  which provided the following install information:

  The following NEW packages will be installed:
    libmcrypt4 php5-cli php5-common php5-fpm php5-gd php5-json php5-mcrypt
    php5-readline php5-sqlite
  0 upgraded, 9 newly installed, 0 to remove and 0 not upgraded.
  Need to get 4,973 kB of archives.
  After this operation, 20.4 MB of additional disk space will be used.
  Do you want to continue? [Y/n]

• now configure php5-fpm:

  $ sudo nano /etc/php5/fpm/php.ini

  change this line in the file:

  ;cgi.fix_pathinfo=1

  to the following:

  cgi.fix_pathinfo=0

• finally, restart the php5-fpm service:

  $ sudo service php5-fpm restart

• create the configuration file for a Nginx virtual server (14lts64-nginx) using php-fpm:

  $ sudo nano /etc/nginx/sites-available/virtual     # copy the below into this empty file

  ##
  # You should look at the following URL's in order to grasp a solid understanding
  # of Nginx configuration files in order to fully unleash the power of Nginx.
  # http://wiki.nginx.org/Pitfalls
  # http://wiki.nginx.org/QuickStart
  # http://wiki.nginx.org/Configuration
  #
  # Generally, you will want to move this file somewhere, and start with a clean
  # file but keep this around for reference. Or just disable in sites-enabled.
  #
  # Please see /usr/share/doc/nginx-doc/examples/ for more detailed examples.
  ##
  
  # Default server configuration
  #
  server {
          listen 80 default_server;
          listen [::]:80 default_server;
  
          # SSL configuration
          #
          # listen 443 ssl default_server;
          # listen [::]:443 ssl default_server;
          #
          # Self signed certs generated by the ssl-cert package
          # Don't use them in a production server!
          #
          # include snippets/snakeoil.conf;
  
          root /var/www/html;
  
          # Add index.php to the list if you are using PHP
          index index.php index.html index.htm;
  
          server_name 14lts64-nginx.lxc;
  
          location / {
                  # First attempt to serve request as file, then
                  # as directory, then fall back to displaying a 404.
                  try_files $uri $uri/ =404;
          }
          location ~ /\.ht {
                  # deny access to .htaccess files, if Apache's document root
                  # concurs with nginx's one
                          deny all;
          }
  
          # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
          #
          location ~ \.php$ {
                  try_files $uri =404;
          #       # With php5-cgi alone:
          #       fastcgi_pass 127.0.0.1:9000;
                  # With php5-fpm:
                  fastcgi_pass unix:/var/run/php5-fpm.sock;
                  fastcgi_index index.php;
                  fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
                  include fastcgi_params;
          }
  }

• Remove the default configuration, and instead use the configuration for the virtual server

  $ sudo rm /etc/nginx/sites-enabled/default
  $ sudo ln -s /etc/nginx/sites-available/virtual /etc/nginx/sites-enabled

• Now restart the nginx & php-fpm services:

  $ sudo service nginx restart
  $ sudo service php5-fpm restart

• To test that .php pages are working, create a single line page to display the PHP info:

  $ sudo nano /var/www/html/index.php     # copy the below into this empty file

  <?php phpinfo(); ?>

• http://14lts64-nginx.lxc/ ← now shows a detailed PHP Information page (using the above index.php)

• http://14lts64-nginx.lxc/test.html/index.php ← returns a 404 error as it should.

• Add the default user ubuntu to the group www-data

  $ sudo usermod -a -G www-data ubuntu

• Add the ssh Public/Private keys to use rsync or sftp to upload and download files directly to/from the Lxc Container.

• Stop 14lts64-nginx and take a snapshot of it:

  $ sudo su
  # lxc-stop -n 14lts64-nginx
  # echo 'Nginx w/ php-fpm just installed & configured' >snapshot-comment.txt
  # lxc-snapshot -n 14lts64-nginx -c snapshot-comment.txt     # output below

  lxc_container: Snapshot of directory-backed container requested.
  lxc_container: Making a copy-clone.  If you do want snapshots, then
  lxc_container: please create an aufs or overlayfs clone first, snapshot that
  lxc_container: and keep the original container pristine.

• List the snapshots w/ any comments:

  # lxc-snapshot -n 14lts64-nginx -LC     # example output below

  snap0 (/var/lib/lxcsnaps/14lts64-nginx) 2015:05:20 16:18:19
  Nginx w/ php-fpm just installed & configured

• now delete the text file created to hold the above comment:

  # rm snapshot-comment.txt
  # exit

• This container is now frozen and should never be used or logged into again! In fact, the only reason to have a snapshot of this container, is to enable putting it back to exactly the way it is now – should anything happen that changes this Lxc Container that has been Preconfigured with Nginx using php-fpm.
• The lxc-clone command will now be used to create Development Containers using the Overlayfs – where only the changes made to this base/master/starting container are actually stored by the file-system for these cloned containers.

• As Example: the Summary Notes for DokuWiki in an Nginx & PHP Container use the following command to create the dokuwiki container – so the DokuWiki package can then be installed & configured in this clone of the 14lts64-nginx container

  #  lxc-clone -o 14lts64-nginx -n dokuwiki -B overlayfs -s

• This use of the Overlayfs for Development Containers also enables truly useful Snapshots – where each snapshot also records only the changes that have been made.

To effectively implement the above, there needs to be some way to know which containers are the “Preconfigured Containers” and which containers are the “Development Containers”. I use the following container name hints to make this immediately obvious on my own Development Workstation:

for ext4 Filesystem Preconfigured Containers

• In the above 14lts64 is how I designate any Ubuntu 14.04 LTS 64bit container. (I would use 12lts64 for Ubuntu 12.04 64bit)
• Any Preconfigured Container – that I create Development Containers from – will always start with an OS designation.
• These are the “frozen” ext4 filesystem based containers that should never be used.
• The only reason to have one snapshot of a Preconfigured Container is to enable restoring it to exactly how it was “frozen”.

for overlayfs Development Containers

• These are named using some combination of an Application (possibly with a version designation) and/or a Project or Site.
• Development Containers never contain one of the (above) “frozen” OS designations anywhere in the container name.
• These are the Overlayfs based containers that are “created & destroyed” to be “used & abused” for Development Work.